AD 81-21-51 R1
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Lockheed Martin Corporation | L-1011-385-1 | LOCKHEED-CALIFORNIA COMPANY Model L-1011-385 Series Airplanes |
| aircraft | Lockheed Martin Corporation | L-1011-385-1-14 | LOCKHEED-CALIFORNIA COMPANY Model L-1011-385 Series Airplanes |
| aircraft | Lockheed Martin Corporation | L-1011-385-1-15 | LOCKHEED-CALIFORNIA COMPANY Model L-1011-385 Series Airplanes |
| aircraft | Lockheed Martin Corporation | L-1011-385-3 | LOCKHEED-CALIFORNIA COMPANY Model L-1011-385 Series Airplanes |
Unsafe Condition
Failure of the Airborne Vibration Monitor (AVM) System to alert flight crews to engine abnormalities, such as sudden vibration increases or oil filter pressure light illumination, could lead to undetected engine failure or malfunction.
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Required Actions
Revise the Airplane Flight Manual to include AVM system operational requirements and emergency procedures, reactivate AVM input to the ENG/APU STATUS light, comply with specified service bulletins, and perform maintenance actions when specified AVM or oil pressure indications occur.
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Compliance Time
Within 25 hours time in service after receipt of this AD or within 3 calendar days, whichever occurs later for paragraph A; within 25 hours time in service for paragraph B; within 75 days calendar time after receipt for paragraph C.
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Affected Aircraft
Lockheed-California Company Model L-1011-385 series airplanes, including L-1011-385-1, L-1011-385-1-14, L-1011-385-1-15, and L-1011-385-3, certificated in all categories.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
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